<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
        <style>
            .one {
                width: 100px;
                height: 100px;
                background-color: yellow;
            }

            .two {
                width: 200px;
                height: 200px;
                background-color: hotpink;
            }

            .three {
                width: 250px;
                height: 250px;
                background-color: red;
            }
            .active {
                color: blue;
            }
        </style>
    </head>

    <body>
        <div id="root">
            <div :class="boxClass"></div>
        </div>
        <script>
            const vm = new Vue({
                data() {
                    return {
                        boxClass: ["one", "two", "three"],
                    };
                },
            }).$mount("#root");
        </script>
    </body>
</html>
